2607/tcp is already used by ospfapi.
Let's use 2608/tcp for isisd.
diff --git a/SERVICES b/SERVICES
index d74098f..9c3546b 100644
--- a/SERVICES
+++ b/SERVICES
@@ -15,4 +15,5 @@
 ospfd		2604/tcp
 bgpd		2605/tcp
 ospf6d		2606/tcp
-isisd		2607/tcp
+ospfapi		2607/tcp
+isisd		2608/tcp